


detective sirius black is on the case

by facingthenorthwind (spacegandalf)



Series: everybody lives (except peter) [5]
Category: Harry Potter - J. K. Rowling
Genre: Alternate Universe - Everyone Lives/Nobody Dies, Book 3: Harry Potter and the Prisoner of Azkaban, Fix-It, Fluff, Gen, The Marauder's Map
Language: English
Status: Completed
Published: 2019-02-04
Updated: 2019-02-04
Packaged: 2019-10-22 06:01:15
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,831
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17657273
Author URL: https://archiveofourown.org/users/spacegandalf/pseuds/facingthenorthwind
Summary: It's 1993 and Sirius Black has sneaked into Filch's office to retrieve the Marauder's Map only to discover... someone has already taken it.But who?





	detective sirius black is on the case

**Author's Note:**

  * For [StormVandal](https://archiveofourown.org/users/StormVandal/gifts).



> This is not compliant with a throwaway line in _iconoclast_ , mostly because I realised this was an enormous plothole. :P And unlike the rest of the fics in this series, it would probably help if you read [nothing better](https://archiveofourown.org/works/16352678) first!
> 
> thanks to kayla and ao3 user renaissance for helping me out with this! <3

"Moony. Moony, I have terrible news."

Remus, who had barely had time to find his footing after coming out of the fireplace, blinked at his husband for a moment in bewilderment. He had a split second of desperate rationalisations — it can't be Voldemort, Voldemort's dead, no one could be dead, someone would've told him, Sirius would have come to his office instead of waiting until he got home, no one could possibly be dead — before Sirius continued.

"Moony, the Map is gone. I went to Filch's office to get it back during lunch—"

"You could've been caught!" Remus found his hands were shaking slightly, and went to fix a cup of tea. No one was dead. Nothing bad had happened. Even his admonition was half-hearted, his brain playing the role he'd been assigned while the rest of him tried to stop panicking. 

"I was a dog, what was he going to do?"

"You're not a permitted pet," Remus said, proud of the way his voice sounded completely normal now. No one was dead and the war had been over for twelve entire years. "Cat, owl, rat or toad. No dog. He could have — I don't know, sent you to the pound?" Just having a hot cup of tea in his hands felt like a balm, and he took a moment to clutch at it before he joined Sirius on the sofa. Wait a second — "Are you wearing my glasses?"

"Yes, they make me feel more scholarly and serious, and this is important detective work."

"What is?" 

“Finding out where the Map is!” Sirius said, as if it were perfectly obvious. When Remus did not respond, Sirius said, at first almost to himself, “I need a pipe. Moony, I need a pipe!”

“You are not smoking in our home,” Remus said, finally feeling like he had both feet on the ground again.

“Did I say I was going to smoke it?”

Remus opened his mouth, closed it, and chose to have a sip of tea. Sometimes it was best to just let Sirius bluster his way through something.

“So I did some sleuthing while I was in Filch’s office — don’t worry, I wasn’t an idiot, I set up precautions—” Sirius added before Remus had a chance to say anything, which just left Remus wanting to ask even _more_ questions, like ‘what’ and ‘how’ and ‘why didn’t you ask for help’. He’d made plenty of noise about disapproving of Sirius’s canine sojourns inside the school, but had never made any effort to stop him, and would absolutely play accessory to the crime if it would help Sirius get away with it. 

He would perhaps not admit those loyalties to McGonagall, but what she didn’t know wouldn’t hurt her.

“—and I think it’s been taken recently. Or at least, recently-ish.”

“... It’s been sixteen years, how could you possibly know? It might have been thrown away or destroyed.”

Sirius lowered Remus’s glasses and looked over them in a way that was eerily reminiscent of McGonagall, but also hammered home that Sirius probably couldn’t see a thing while looking through them. “We would know. We’d feel it.” He put his hand over his heart. “Besides, Filch has never thrown away anything in his life. The rest of the cabinet was dustier than our file.”

“So how recently is recently-ish?” Remus said, taking another sip of tea. He swung his legs up onto the sofa and dug his toes under Sirius’s thigh; Sirius had balanced an inkwell and a notebook on his lap, and Remus didn’t want to knock them off. Sirius immediately leant forward to put them on the coffee table and brought Remus’s feet onto his lap, making small circular motions on Remus’s ankle with one hand as he used the other to gesticulate.

“Within the last year or two?” he offered, shrugging, and stole Remus’s mug to take a large gulp of tea. Remus found it terribly unfair that Sirius could steal his tea but the way Sirius took his was far too unpalatable for Remus to return the favour. 

“You can’t tell that from dust patterns,” Remus pointed out, rolling his eyes. “You’re full of it.”

“Oi! You’re just not a careful connoisseur of dust like I am. No need to be jealous.” He sniffed, affecting an expression that put Remus in mind of some of the older Slytherins he taught.

“Well, Detective Inspector, what’s the next step? Questioning every wizard in the country who could possibly have breathed within twenty kilometres of Filch’s office? Surely it’d be easier to make a new map.”

Remus regretted the words as soon as they came out of his mouth. They couldn’t make a new one — it wouldn’t be the same, it couldn’t be. There was a brief lull as they both mourned all the ways the world had changed since that madcap year they’d spent drawing up all the corridors and perfecting the spellwork. Before Remus could get too maudlin, Sirius rallied, speaking again.

“If I have to speak to every wizard in the country I’ll do it, but I think the better idea is asking who was in a position to steal it,” Sirius said, a grin slowly curling at the edges of his mouth. “It couldn’t be just _anyone_ , after all — it had to be someone who was in Filch’s office for some reason, whether they sneaked in or Filch left them there momentarily. And I doubt you’d think of going through old filing cabinets on your first visit — you’d have to be spending ages in there, really taking stock of the scenery before it’d occur to you.”

“I think you’re making a lot of assumptions, but I don’t see any better way to go about it,” Remus said, shifting slightly on the sofa to be more comfortable. “And how are you going to find that out? Filch certainly wouldn’t tell you, and I’m fairly sure he still loathes me. He’s reluctantly deferential, but only because I’m a teacher.”

Sirius pulled a face. “Of course I’d never ask Filch, who do you take me for? No, we need someone who’s been teaching from when we were at school until now. Sluggy’s gone, Binns is as useless as ever, Kettleburn has gone and lost too many limbs… Minnie would know!” Sirius sat up suddenly, jostling Remus’s legs. “And she loves you! And also me.”

“She asked me to call her by her first name because we’re colleagues,” Remus said, failing to hide a smile. “I don’t think that’s love.”

“Shh, she loves you,” Sirius said, waving a hand in his direction. “Can you have tea with her? No, convince her to have tea with both of us. I’m sure she’s missed me.”

“I’m sure she has,” Remus said, laughing and shaking his head.

* * *

“To what do I owe the pleasure, gentlemen?” McGonagall said as they both sat down. She poured them both tea and watched as Sirius emptied half the sugar bowl into his. 

There was a pause as Sirius opened his mouth and then closed it. Remus realised at the same moment Sirius did that they did not have an explanation for this that did not involve the Marauder’s Map. For reasons Remus could not identify, despite the fact that he was a fellow teacher and also thirty-three, the concept of telling her about the Map was utterly anathema to him. 

“Sirius is concerned about his legacy,” Remus said at last, smirking.

“ _Our_ legacy,” Sirius added. “What I want to know is whether there have been any students after us that reached our heights of genius. Truly inspired pranksters. Veterans of detention. Thorns in the side of everyone who wants the school to run in a sensible, orderly manner.”

McGonagall raised her eyebrows and took a sip of tea. Remus took the opportunity to eat a gingersnap, which she had very thoughtfully put out next to the teapot. There was something special about McGonagall’s gingersnaps that he hadn’t been able to find anywhere else — though it may just have been the thrill of having a biscuit offered to you by a teacher. He was delighted to find the thrill remained, even now.

“There have only been two groups of students that could hold a candle to your reign of terror,” McGonagall said. “Horton, Sato and Grouse were thankfully primarily Filius’s problem, but still made far too much of an impression given none of them were in my house.”

Sirius frowned, mouthing the names to himself. “What year were they?”

McGonagall paused as she took a moment to remember. “They graduated in eighty-seven.”

Sirius’s frown deepened. Remus had never heard of any of them, and while it wouldn’t be _that_ hard to track them down — Wizarding Britain was not terribly big, after all — it was clearly more trouble than Sirius had envisioned.

“And who were the others?” Sirius asked.

“The Weasley twins,” McGonagall said, shaking her head. “If I didn’t know better I’d say they were apprenticing under you.” She narrowed her eyes suspiciously. “You aren’t going to take them under your wing, are you? They are already far too proficient in all manner of mischief. I dare say they might be able to teach _you_ things.”

“Well, we weren’t,” Sirius said, shit-eating grin firmly in place, “but now that you’ve made it such an attractive proposition, I don’t see how we could refuse.” He laughed at the look McGonagall gave them both. 

“If I hear you giving either Weasley twin tips, Remus, I will let Peeves loose in your office. I have been here a long time and Peeves and I could no doubt come to an… agreement.”

Sirius stopped laughing, but only because he began choking on his own spit instead. Remus thumped him on the back and felt absolutely no sympathy.

“Understood,” Remus said, taking another gingersnap.

* * *

Remus Lupin was very sure that Minerva McGonagall contained multitudes, much of which he would never be aware of. He was also very sure that she had never bluffed in her life, and was not about to call her on this one — which meant that there was somewhat more subterfuge than he would ideally like given all he was doing was asking to see students that he taught in his office.

Mercifully, he had the Fifth Year Gryffindors last thing on a Thursday and all he had to do was ask them to stay behind. Sirius was already in his office, looking very dignified (and, notably, completely human) as he sat in Remus’s chair. Remus gave him a dirty look and summoned another chair to sit in.

“You’re not in any trouble, first of all. Fred, George, this is Sirius Black. Sirius, Fred and George Weasley.” Sirius got up and shook each boy’s hand, the seriousness ruined by his grin. “We just want to ask you a few questions.”

“Now who’s sounding like a copper in a Muggle murder mystery?” Sirius said to Remus before turning to the boys and putting his hands on the table.

“Many years ago, M— Professor Lupin and I lost something very important, and I’m hoping you might know where it is.”

“I didn’t lose it,” Remus muttered under his breath. “That was all you and Prongs.”

He hadn’t intended for it to be some kind of test, but the way both twins looked at him immediately made him sure that they had the right people. It wasn’t quite a look of recognition in their eyes, but there was too much interest there for it to be a coincidence.

“Regardless, we were wondering if you had ever, perhaps, taken a look at Filch’s old files. Confiscated items. Perhaps you came across a large, blank piece of parchment?”

The twins looked at each other with identical broad grins. They looked as if Christmas had come early. 

“We might have,” Fred said, his eyes flickering to Remus.

“I have no interest in confiscating it,” Remus assured him, putting his hands up. “Far be it for me to forbid an item I helped create.”

Remus had thought it impossible for their grins to get any wider, but they did, both boys then speaking at once.

“Which one are you—”

“How did you do—”

They both paused, and George made an exaggerated gesture of allowing Fred to go first.

“Are you Moony, Wormtail or Padfoot?” Fred asked, looking as if he were ready to vibrate out of his seat.

“Moony,” Remus said, “and this is Padfoot. You might know Prongs — he’s Harry Potter’s father, Ron’s friend.”

They took a moment to absorb that before Fred said, “And Wormtail?”

Remus looked at Sirius. They should have expected this, but somehow it completely blindsided them both. There was a too-long pause before Sirius said, “He was killed in the war.”

“I’m sorry,” George said, and Fred nodded, both of their grins disappearing. They had lost uncles, hadn’t they? He was pretty sure Gideon and Fabian’s little sister was their mother. They would have been too young to remember them, but he knew from Harry that they had several older brothers who doubtless could remember.

“It’s alright, it was a long time ago,” Remus said. He tried not to think about whether or not it was a lie.

“Have you worked out how to use the Map?” Sirius said, visibly trying to steer the conversation away from thinking too much about Peter and the war. If they wanted to get drunk and weepy they could go to Godric’s Hollow. 

“Yeah,” Fred said, and rummaged in his bag a moment before producing the Map. Sirius’s face lit up and he looked like he was a moment away from snatching it; instead, Fred put it on the table and Sirius eagerly grabbed it, murmuring “I solemnly swear I am up to no good,” as if it were second nature. 

The entire castle spread out before him, spidery lines of ink running from the tip of his wand to cover the parchment. People moved endlessly — there was McGonagall, in her office; Filch, prowling the fourth floor; Harry, Ron and Hermione in the common room. Remus unexpectedly felt his throat tighten — when Dumbledore had offered him the job, he hadn’t mentioned how often he would feel like he had time travelled a decade or two.

“And you must also know how to make it blank again,” Sirius said, to which the twins nodded. Sirius leant back, smiling fondly at the twins in much the same way Remus had seen him look at Harry. “I’m so glad you were the ones to find it. Truly, I can’t think of more worthy inheritors of our legacy.”

“Professor McGonagall says you’re even better than we were,” Remus said, smiling at the way the twins looked at each other with surprise and delight. “She threatened me, so you can’t let on that this meeting happened, otherwise it might look like I’m taking you under my wing, and then…” Remus trailed off, not sure what McGonagall would actually do in that eventuality. He had removed all the most treasured things from his office last night anyway.

“The secret’s safe with us,” George said, miming zipping his lips. “Can the Map do anything else?”

“Hmm,” Sirius said, frowning. “It is the only known functional map of Hogwarts, complete with all moving passages and every person in the castle, so it’s already doing quite a lot. But — oh!” He sat up, and Remus wasn’t sure he liked the expression on his face. “We did make it so that if Snivellus found it, it would insult him.” At the inquiring expression on the twins’ faces, Sirius added, “Snape, I mean.”

Remus wanted to sink into the floor. He was a colleague!

“And it would compliment Professor McGonagall,” Sirius added. “But that’s it, I’m pretty sure.”

They’d spent an entire night coming up with things for it to say, huddled on James’s bed and giggling as they ate Bertie Botts. Remus’s chest ached a little.

“Incredible,” Fred said, still looking a little like he couldn’t believe that he was sitting in the same room as two of the creators of the Marauder’s Map. 

“We’ve been trying to copy it,” George said, looking a little guilty. “So we both have one, for when we split up. We’ve been having trouble, though.”

“It’s a really complex piece of magic,” Sirius said. “Which bits aren’t working right when you copy it?”

Remus watched (and occasionally pitched in; he may have been a teacher, but he was still a Marauder at heart) as Sirius taught the next generation how to do bigger, better mischief than they’d ever achieved. By the end of the night, the four of them had missed dinner but had three fully functioning Marauder’s Maps (the third was for Harry; Sirius was going to give it to him for Christmas). They used Harry’s to make sure Professor McGonagall didn’t see the Weasleys leave Remus’s office.

Living in fear of Peeves for the rest of the year was worth it, honestly.


End file.
